Drip irrigation system employing adjacently arranged flow-restricting passages

ABSTRACT

An elongated fluid distributing hose for use in an irrigation system for plants, vegetables, and the like. The hose incorporates a particular arrangement of a main supply channel for gross water movement, and a water distributing network for fine water movement. The major water pressure reduction takes place in the water distributing network made up of a series of first, second, and third fluid-restricting passages and is eventually released to the exterior of the hose through a series of discharge fluid-passing openings or outlet stations. A novel method and machine are employed to manufacture the hose embodying the teachings of the subject invention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a water distributing hose for use in a trickleirrigation or drip irrigation system.

2. Background of the Prior Art

The present invention relates to irrigation systems particularly adaptedfor the surface or subsurface watering of long runs of crops, whether ongreenhouse benches or in the field, and more specifically relates to atrickle irrigation system wherein the water is allowed to dischargeslowly, directly at the desired point of application, normally about thebase of the plants.

Recent innovations in irrigation technology have been directed to theconcept of trickle irrigation. As an example, in row crops, it is onlynecessary to irrigate the rows and not the entire field. Such a limitingof the watering to the rows by trickle irrigation can effect a watersaving of approximately 40 to 50 percent. As the need for food for theworld's expanding population increases and water shortages become moreacute, such savings will become increasingly more important. In thisconnection, trickle irrigation is especially significant because itdelivers water at or below the surface and provides for a significantconservation of water.

Since there is considerably less water used in trickle irrigation, it isimportant that the water be directed precisely to the plant's root area.The flow from some known prior art hoses comes out in a tiny squirt,which can be blown by the wind so that sometimes it does not uniformlywet the area next to the plant row. When an irrigation hose is locatedon top of the soil, it is often twisted slightly by the contour of thesoil. This causes the squirt to come out at different angles. The waterfrom some of the squirts could fall next to the plant row and othersquirts would be directed between the rows of plants leaving some rootareas dry.

When the irrigation hose is used under a plastic mulch, as is frequentlydone, the flow sometimes squirts against the underside of the plasticmulch which deflects the water and causes part of it to follow on theunderside of the plastic and run off into the aisle between the plantrows. The squirt sometimes has enough force to cause a tiny washout onelevated beds so that water runs down the side of the bed into the aislerather than remaining on top of the bed surface and uniformlypenetrating the entire bed.

To be practical, trickle irrigation must provide for the delivery ofwater at a slow uniform rate over long lengths or runs of hose. In thepast, various trickle irrigation systems have been tried, includingpipes with small holes, pipes with various types of small outletmembers, pipes with small tubes for outlets, plastic pipes with slits,tubes which ooze water through the wall, and hoses which ooze waterthrough a sewn seam. Each type has depended on a small orifice, lowpressure, friction created in a long outlet member such as a tube, or acombination of these to limit the flow through each individual outlet.However, there are disadvantages associated with each such known system.For example, the use of extremely small orifices such as holes, slits,or the like, tend to clog easily. Tube outlets and special outletmembers are relatively expensive to produce and ship, particularly whenconsidering the large quantities required. In addition, low pressuresystems and tubes which provide for an oozing of the water through thewall are not capable of producing a uniform flow along the length of thehose or the like, particularly on sloping runs.

Since drip irrigation hoses are commonly made with wall thicknessesranging from 0.003" to 0.030", the hoses are sometimes subject to damagefrom ants. When this occurs, ants have been known to go through the mainwall of the hose, but usually they will chew around the edges ofexisting discharge openings, enlarging them, sometimes to several timestheir original diameter. This causes the hose to have a heavy water flowat the enlarged discharge opening and a much lower flow in other nearbyopenings, resulting in a non-uniform irrigation.

One water distributing hose which has met with success is that disclosedin U.S. Pat. No. Re. 28,095, reissued July 30, 1974 to Chapin. In thereissue patent, a multi-chamber water distributing hose is shown in thecontext of a trickle irrigation system. Another hose which has met withsuccess is that disclosed in copending U.S. patent application Ser. No.261,699, filed May 8, 1981, in the name of Chapin, now abandoned infavor of File Wrapper Continuation Ser. No. 559,853. The hose of theChapin application is an elongated water distributing hose capable ofeffectively watering large areas with readily available water pressuresand in a manner whereby an essentially uniform watering is achieved. Thepressure is substantially maintained throughout the length of the hosethrough a stacked arrangement of first, second, and third fluidchannels, which enable a maintaining of the relatively high pressurethroughout the length of the hose and the reduction of this pressuredirectly at the point of the passing of the water from the high pressurefirst fluid channel through a series of first fluid-passing openings tothe much smaller second fluid channel, and a further pressure reductionas the water passes within the third fluid channel between a series ofsecond fluid-passing openings and a series of discharge fluid-passingopenings.

Still another hose is that disclosed in copending U.S. patentapplication Ser. No. 364,213, filed on even date herewith and entitled"Drip Irrigation System Employing Flow Regulation".

Although the performance of all of the Chapin hoses has been excellent,there is, nevertheless, always a need for improved performance. Thepresent invention is directed toward filling that need while at the sametime minimizing the disadvantages described above in connection withknown systems.

SUMMARY OF THE INVENTION

The present invention relates to an elongated fluid distributing hosefor use in an irrigation system for plants, vegetables, and the like.The hose of the present invention enables the construction of a dripirrigation system which is relatively inexpensive while at the same timecapable of effectively watering large areas with readily available waterpressures and in a manner whereby an essentially uniform watering isachieved. This desired uniform watering results notwithstanding slopingground conditions and the like. Water pressure is substantiallymaintained throughout the length of the tube without requiring the useof extremely small orifices which easily clog from impurities, relianceinstead being had on a particular arrangement of a main supply channelfor gross water movement, and a water distributing network for finewater movement. The main supply channel exhibits relatively high waterpressure throughout the length of the hose. A reduction of this pressuretakes place in the water distributing network with the passing of thewater from the high pressure main supply channel through a series offirst fluid-passing openings or inlet stations to a much smaller firstfluid-restricting passage. In much the same way, the fluid is passedthrough second and third fluid-restricting passages and is eventuallyreleased to the exterior of the hose through a series of dischargefluid-passing openings or outlet stations.

The hose of the instant invention is preferably of a thinwater-impervious plastic material, such as polyethylene. The main supplychannel moves the water at a relatively high pressure along the fulllength of the hose for discharge into the water distributing network forfinal discharge out of the hose itself through a number of openings oroutlet stations in the outer passage. The pressure decrease within thewater distributing network is such that the flow of water at the outletstations of the network is in the form of a drip under substantiallyquiescent conditions.

A novel method and machine are employed to manufacture the hoseembodying the teachings of the subject invention. Basically, the hose ismanufactured by moving an elongated impervious film in a givendirection. The film is oriented to expose an outer surface and margin ofthe film. Disposed on this outer surface in a parallel array is aplurality of hot melt plastic beads. The beads are placed on the film bya conventional extrusion nozzle. The beads are positioned so that theyextend along the margin, essentially parallel to the longitudinal axisof the elongated film.

The film continues to move in the given direction and transports thepreviously deposited hot melt beads to a molding station where each ofthe beads is molded by deformation in a predetermined manner by amolding tooth to create a permanent depression within each of the beads,thereby molding each hot melt bead into a series oflongitudinally-extending, spaced apart strips. The spaces created by themolding tooth eventually become the fluid passing openings between thevarious flow channels.

The film continues to move through a guide which causes the flatmaterial to be folded upon itself so that the interior surface of theother margin of the film comes into contact with the hot melt beads. Thestructure then passes through a pair of forming wheels which places thetop film in intimate contact with the top of the hot melt strips causingthe top film to bond to the spaced apart strips at a precise distancefrom the common wall of the film thus creating the flow restrictingpassages.

Advantages and objects of the present invention include the provision ofa system which can be inexpensively produced, such being essentialbecause of the vast quantities of hose needed to irrigate field cropinstallations which typically involve thousands of acres. The system iscompact, the hose capable of being flattened and rolled, therebysimplifying the handling, storage, shipping, installation and removal.The hose used is of a highly durable nature. In addition, large areascan be simultaneously watered without requiring excessively highpressures or large volumes of water with the distribution of the waterbeing uniform over extremely long lengths as well as on sloping layoutsand in both surface and subsurface installations.

These together with other objects and advantages, which will becomesubsequently apparent, reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a portion of a field making use ofthe irrigation system of the present invention.

FIG. 2 is a perspective view of a portion of a hose embodying theteachings of the subject invention.

FIG. 3 is a section taken along lines 3--3 of FIG. 2.

FIG. 4 is a view similar to that of FIG. 2 with a portion of the hoseremoved to reveal the interior structure of the flow restrictingpassages.

FIG. 5 is a schematic view of a second embodiment of a hoseincorporating the teachings of the present invention.

FIG. 6 is a schematic view useful in explaining the operation of thehose of FIG. 4.

FIG. 7 is a view taken along lines 7--7 of FIG. 6.

FIG. 8 is a view taken along lines 8--8 of FIG. 6.

FIG. 9 is a cross-sectional view of the embodiment of FIG. 6.

FIG. 10 is yet another embodiment of a hose incorporating the teachingsof the subject invention.

FIG. 11 is a schematic diagram used to help explain the operation of theembodiment of FIG. 10.

FIG. 12 is a schematic diagram of still another embodiment of a hoseincorporating the teachings of the subject invention.

FIG. 13 illustrates yet another embodiment of a hose adopting theteachings of the subject invention.

FIG. 14 shows a modification made to the embodiment of FIG. 1.

FIG. 15 is a view taken along lines 15--15 of FIG. 14.

FIGS. 16 and 17 show yet another modification to the embodiment of FIG.2.

FIG. 18 is a perspective diagrammatic drawing to illustrate anembodiment of a machine used to manufacture a hose according to theteachings of the present invention.

FIG. 19 is a view taken along lines 19--19 of FIG. 18.

FIG. 20 is a view taken along lines 20--20 of FIG. 18.

FIG. 21 is a schematic diagram illustrating the operation of the machineshown in FIG. 18.

FIG. 22 is a view taken along lines 22--22 of FIG. 21 and is used toshow the placement of a hot melt bead onto the thermoplastic filmforming the outer portion of the hose.

FIG. 23 is a view taken along lines 23--23 of FIG. 21 and is used toschematically illustrate the formation of an indentation in the hot meltbead.

FIG. 24 is a view taken along lines 24--24 of FIG. 21 and is used toschematically illustrate the placement of two hot melt beads and theirpassage through the pair of forming rolls during the manufacture of thehose.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In describing a preferred embodiment of the invention illustrated in thedrawings, specific terminology will be resorted to for the sake ofclarity. However, the invention is not intended to be limited to thespecific terms so selected, and it is to be understood that eachspecific term includes all technical equivalents which operate in asimilar manner to accomplish a similar purpose.

With reference to FIGS. 1-4, reference 10 is used to generally designatethe water distributing hose embodying the teachings of the presentinvention. The hose 10 basically comprises a gross water distributingchannel 12 and a fine water distributing network 14. Adjacent to channel12 and sharing a common wall 16 is the network 14, which basicallycomprises a plurality of flow restricting passages 18-20, positioned onenext to the other in a common curved plane and disposed about theexterior of the main supply channel 12. Each of the passages issubstantially equidistant from the longitudinal axis A of the mainsupply channel. As can be seen, the three fluid passages 18-20 arearranged in a generally parallel relationship throughout the length ofthe hose.

In use, the main supply channel 12 is connected to a source ofpressurized water. This can be effected, for example, by connecting themain supply channel 12 at one end of hose 10 to a suitable fitting 21 inmain 25. The other end 11 of the hose 10 is closed off to prevent escapeof the water entering the hose. Such an arrangement has been generallyillustrated in FIG. 1 wherein the hose 10 is illustrated next to rows ofvegetables in a large field. It will be appreciated that such anarrangement is also equally adaptable for use in greenhouses and homegardens.

With reference to FIGS. 2 through 4, an elongated layer or sheet 22 ofthin water-impervious plastic material, such as a thermoplastic film,terminates in two longitudinally extending margins 24 and 26 whichoverlap each other in a predetermined fashion. Interposed between theoverlapping margins are a series of elongated longitudinally extendingstrips of varying lengths and arranged in a particular manner, yet to bedescribed, to define the fine water-distributing network 14. The stripsare also made from a water-impervious plastic material.

A first set of strips 30 are positioned near the edge 32 of margin 24,so that each of the strips define an axis substantially parallel to andequidistant from the longitudinal axis A of the hose 10. The ends 34 ofthe strips are periodically spaced from each other to define inletstations as a series of fluid-passing openings 36 therein. The frequencyof the inlet stations typically ranges from a few inches to several feetthroughout the full length of the hose. The inlet stations or firstfluid-passing openings 36 are positioned so that they form a means offluid communication between the main supply channel 12 and the firstflow-restricting passage 18 of the network 14. The spaces between thestrips 30 define the first inlet stations 36 and the strips 30, ineffect, define a common wall 33 between the main supply channel 12 andthe first passage 18.

In like manner, a second set of strips 40 are positioned near to, butspaced from, the wall 33 defined by strips 30. The second set of stripsalso have their ends 44 spaced from each other to define a further setof fluid-passing openings or inlet stations 46, to form a means of fluidcommunication between the first passage 18 and the secondflow-restricting passage 19. Thus, the second fluid-passing openings 46are positioned somewhere along the common wall 43 between the first andsecond passages 18 and 19 as defined by the strips 40. The secondfluid-passing openings 46 generally have substantially the same spacingbetween them as the spacing formed between the first fluid-passingopenings or inlet stations 36. In actual practice, the spacing of thesecond fluid-passing openings 46 can vary from a few inches up toseveral feet.

Additionally, a third set of strips 50 are positioned near to, butspaced from, the wall 43 defined by strips 40. The third set of stripsalso have their ends 54 spaced from each other to define a third set offluid-passing openings or inlet stations 56 to form a means of fluidcommunication between the second passage and the third flow-restrictingpassage 20. Thus, the third fluid-passing openings 56 are positionedsomewhere along the common wall 53 between the second and third passages19 and 20 as defined by the strips 50. The third fluid-passing openings56 generally have substantially the same spacing between them as thespacing formed between the first fluid-passing openings 36.

Finally, a fourth set of strips 60 are positioned near the edge 62 ofthe margin 26 so that the strips define an axis substantially parallelto the longitudinal axis A of the hose 10. The placement of the strips60 is such that they are positioned near to, but spaced from, the wall53 defined by strips 50. The ends 64 of the strips are spaced from eachother to define a fourth series of fluid discharge openings or outletstations 66 to provide for fluid communication between the third passageand the exterior of the hose. In the preferred embodiment, the spacingbetween the outlet stations 66 is substantially the same as that betweenthe third inlet stations 56.

In the preferred embodiment, the inlet and outlet stations 36, 46, 56and 66, which may also be referred to as cross passageways, aresubstantially of a rectangular cross section and precisely formed by thepositioning of the strips between the overlapping margins 24 and 26. Thesize of the outlets at each station is chosen so that there is a minimumchance of clogging as water passes through the station.

For the purposes of simplifying the presentation, the fluid passingstations 36, 46, 56 and 66 in FIGS. 1-4 are shown in the context of aless preferred embodiment as a single opening. However, in a morepreferred embodiment, such as that shown in FIG. 5, three or moreopenings are used close together to comprise each station. By example,the three openings 66' constitute one fluid passing station whichprovides multiple openings at each station so that if one opening shouldclog, the other two openings can carry the flow through the station.

It is understood that a larger number of closely spaced fluid passingopenings may constitute the first, second and third inlet stations 36,46 and 56 and the discharge stations 66 as long as the totalcross-sectional area of the openings associated with each station exceeda minimum size so that there is a minimum amount of clogging across thestation.

In the preferred embodiment, having 8 inches between the centers of likefluid passing stations, the dimension of each fluid passing opening isapproximately 0.060 inches in width, a height substantially the same asthe height of strips 30, 40, 50 and 60 or about 0.014 inches and alength of about 0.070 inches which is substantially the same as thewidth of the strips.

The length of the flow passage through each fluid passing opening issubstantially longer than the mean average between the width and heightdimensions of the fluid passing opening. In effect, each fluid passingopening is in itself a short pressure-drop channel. With reference toFIG. 6, this pressure-drop phenomena may be explained as follows. Usingflow channel 19 as exemplary, the flow from segment 19A of flow channel19 comes directly toward the flow from segment 19B which is coming fromthe opposite direction and they meet at the fluid passing opening 56A.Each flow thus makes a 90° turn and flows straight for 0.070 inchesthrough the length of fluid passing opening 56A. The flows are thendivided and each flow makes a 90° turn into flow restricting segments20A and 20B of flow channel 20. It is desirable to have the length ofthe fluid passing opening (for example, 56A), which is also thethickness of wall 50, at least three times the thickness of the commonwall 16 to get an increase in friction and pressure loss as the flowmakes two sharp 90° turns in going through the fluid passing openingsfrom one flow restricting passage to another. The same relationshipexists for the lengths of the remaining fluid passing openings 36, 46and 66 relative to the thickness of common wall 16. Of particularsignificance is the provision of this 3 to 1 minimum ratio with regardto inlet stations 36 and outlet stations 66.

In the preferred embodiment of FIG. 2, using a 6 mil. polyethylene film,all fluid passages 18-20 have a generally rectangular configuration witha height of approximately 0.014 inch and a width of about 0.070 inch.The first fluid-passing openings 36 are spaced approximately eightinches apart. The second fluid-passing openings 46 are spaced eightinches apart with each opening 46 being located intermediate between,but spaced from, a pair of openings 36. The third fluid-passing openings56 are spaced eight inches apart with each opening 46 being locatedintermediate between. Finally, the outer openings 66 are spaced eightinches apart with each opening 66 being located intermediate between,but spaced from, a pair of openings 56.

In a preferred embodiment, as the main supply channel 12 of hose 10 ispressurized at 8 psi, water flows through first inlet stations 36located in wall member 33 which separates channel 12 and passage 18. Theflow is then divided and moves within passage 18 to the nearest secondinlet station 46 on either side of the first inlet station 36.Flow-restricting passage 18 has a length between inlet stations and across section of a size to reduce the pressure by approximately 1.0 psiwithin passage 18 between first fluid inlet stations 36 and second inletstations 46.

Water then flows through the second fluid passing openings or inletstations 46 located in wall member 43 between passages 18 and 19 intopassage 19 with an approximate 0.2 psi pressure loss. The flow is thendivided and moves within passage 19 to the nearest third fluid passingopenings or inlet stations 56 on either side of each of the second fluidpassing openings 46. Flow-restricting passage 19 has a length betweenopenings and an interior cross section of a size to reduce the pressureby approximately 1.5 psi within passage 19 between fluid passingopenings 46 and fluid passing openings 56.

The water then flows through fluid passing openings or inlet stations 56located in wall member 53 between passages 19 and 20 with an approximate0.5 psi pressure loss into passage 20. The flow is then divided andmoves within passage 20 to the nearest discharge fluid passing opening66 on either side of fluid passing opening 56. Flow-restricting passage20 has a length between openings and an interior cross section of a sizeto reduce the pressure by approximately 4.7 psi within passage 20between the third fluid passing opening 56 and the discharge fluidpassing opening 66. The flow is then discharged to the exterior of thehose through discharge fluid passing openings or outlet stations 66 inwall member 63 with a slight pressure loss of about 0.1 psi.

Because of the friction created as water passes through the small thirdfluid passage 20, the pressure adjacent to the discharge fluid-passingopenings 66 is negligible (such as 0.1 psi or less), and the wateractually drips out through the openings 66 under substantially quiescentconditions under almost no outward pressure.

The pressure drop loss between any inlet station and its nearestupstream station depends on the width and height of the intermediateflow restricting passage, the length of the same passage, and the rateof water passing through it.

In summary, and with reference to FIG. 6, beginning with 8 psi in themain supply channel 12, there are substantially six steps of pressurereduction as follows: 1. There is approximately 1.0 psi pressure losswithin each segment, for example, segment 18C, of flow restrictingchannel 18; 2. There is a slight (approximately 0.2 psi) pressure lossacross the second fluid passing openings, for example, opening 46B; 3.There is a pressure loss of approximately 1.5 psi within each segment,for example, segment 19B, of the second flow restricting channel 19; 4.There is another slight (approximately 0.5 psi) pressure loss across thethird fluid passing openings, for example, opening 56A; 5. There is asubstantial (approximately 4.7 psi) pressure loss within each segment,for example, segment 20A, of the third flow restricting channel 20; 6.Lastly, there is a very slight (approximately 0.1 psi) pressure lossacross the discharge fluid passing openings, for example, opening 66B.Because the pressure loss across each discharge fluid passing opening ison the order of 0.1 psi, insect attacks to the discharge openings willhave relatively little effect on the overall operation of the hose.

The flow characteristic for a hose of the preferred embodiment that hasdischarge outlets spaced at 8 inches and a total discharge rate of 0.5gpm per 100 feet can be described as approximately 0.00333 gpm passingthrough each fluid passing opening 36, 46, 56, and 66 and approximately0.01666 gpm passing through each flow restricting passage segment, suchas those represented by 18A, 19A and 20A.

The preferred embodiment of the hose functions well in the frequentlyfound uneven field conditions where there are sharp variations in thesoil elevation such as a mound. There is substantially no flow from onesegment of the flow restricting passage to another segment within thesame flow restricting passage. Referring to FIG. 6, a portion of thewater from inlet opening 36B flows into segment 18C where it continuesto flow toward inlet opening 46B until it meets the flow of segment 18Bwhich is coming from the opposite direction. The flows from segments 18Band 18C coming from opposite directions come together at inlet opening46B where they both flow through opening 46B into the flow restrictingpassage 19. Since the flows of each segment in all the fluid restrictingpassages flow alternately in opposite directions, there is substantiallyno flow from one segment to another in any of the flow restrictingpassages 18-20 even if the hose 10 is on a sharp incline as much as 45°.Water supplied to a particular outlet opening 66 comes from inletopenings 36A, 36B, 36C and 36D all of which are within 12 inches of theoutlet opening 66. Since there is substantially no longitudinal flowbetween segments in the flow restricting passages, and the outletopenings are essentially opposite their inlet openings, the flow rateout of a particular outlet opening 66 is affected by the pressure in themain supply channel at a point closest to the outlet opening 66. Thehose of the preferred embodiment, with 8 psi in the main supply channel,placed in a field over a mound of soil 20 inches high still has arelatively uniform distribution pattern with only about a 10% decreasein flow on top of the mound as compared to the surrounding soil level.

The flow rate of the preferred embodiment is generally linear with thepressure in the main supply channel, so that the flow from an outletopening at any given point along the hose is increased or decreased atsubstantially the same rate that corresponds to a pressure increase ordecrease at that same point within the main supply channel.

An important aspect of the present invention is a self-cleaning featurewithin the third flow-restricting passage 20. Most of the total pressurereduction takes place within the segments of the third flow restrictingpassage 20. It has been observed that in the preferred embodiment morethan 58% of the total pressure loss takes place within the segments (forexample, segments 20A and 20B) of the third flow-restricting passageeven though they have substantially the same length and cross-sectionaldimensions as the first flow restricting passage 18 in whichapproximately 12% of the total pressure loss takes place and also havesubstantially the same dimensions as the second flow restricting passage19 in which approximately 19% of the pressure loss takes place.

FIG. 3 illustrates the cross-sectional view of the flow restrictingpassages 18, 19, and 20 in their normal configuration or as pressurizedat a low pressure. FIG. 7 is a cross-sectional view of the flowrestricting passages 18-20 at a point next to a fluid passing opening56. FIG. 8 is a cross-sectional view of the flow restricting passages18-20 at a point next to the discharge fluid passing openings 66. InFIG. 3, the common wall 16 is in its normal relaxed state, such as whenthere is no pressure or a low pressure (1 psi) in the main supplychannel 12. The flow restricting passage 20 is open and relatively freeflowing so that any minute impurities in the water will flush onthrough. However, when the working pressure of 8 psi is applied to themain channel there is approximately a 3.2 pressure differential acrossthe common wall 16 at point 27A as shown in FIG. 7 causing the flowrestricting passage 20 to be smaller due to outward deflection of thecommon wall 16 at point 27A. At the same time FIG. 8 shows a greateroutward deflection of common wall 16 at point 27B due to theapproximately 7.9 psi pressure differential across the common wall 16.The cross-section view of FIG. 7 is at the inlet fluid passing opening56A (FIG. 6) of the flow restricting passage segment 20A and FIG. 8 isat the discharge fluid passing opening 66B of the flow restrictingpassage segment 20B. The amount of deflections of the common wall 16into the flow restricting passage segment 20B gradually increases fromthe indentation at 27A in FIG. 7 to a substantial indentation at 27B inFIG. 8. When under working pressure, the cross-sectional area of theflow restricting passage segment 20B is substantially smaller thansegments 18A and 19A. This smaller cross-sectional dimension providesthe necessary pressure loss within segment 20B to give the desired flow.Yet segment 20B returns to its normal cross-sectional dimensions (FIG.3) when the pressure is reduced at the end of the watering cycle. Thesegment 20B is self-flushing when it is in its normal configuration at alow pressure at both the beginning and end of the watering cycles. Anyminute particles that may have accumulated during the watering cycle,due to the reduced size of segment 20B, are flushed at at this time.

As shown in FIG. 4, the main supply channel 12, formed by wall member22, becomes circular when pressurized, forming a round tube essentiallyfree of internal partitions or other obstructions that would provideadditional surfaces in the flow channel causing more loss of pressuredue to friction, as well as making the hose more difficult to collapsefor storage and shipment.

As the hose is installed in the field, it is preferable to orient thehose so that the flow-restricting passages are on top. Foreign particlesin the water normally settle to the bottom of the main supply channeland are less apt to enter the fluid passing openings and flow passageswhen they are on top of the hose.

Three elements are combined to cause the flow from the discharge fluidpassing openings 66 to tend to fall directly below each opening 66 asshown in FIG. 9. First, the discharge fluid passing openings 66 arelocated in an upper quadrant of the hose rather than in the middle andon top of the hose. Second, the flow from the discharge openings 66tends to come out approximately normal to the last set of strips 60 andpointed in a slightly downward angle when the hose is pressurized and inits normal upright position. Third, the common wall 16 forms one portionof the perimeter of each discharge fluid passing opening 66 so that theflow is in direct contact with the outer wall 28 as it passes throughthe discharge fluid passing openings and tends to cling to the surfaceof the outer wall 28 until it drops on the soil directly below eachdischarge fluid passing opening 66.

Referring to FIG. 6, each fluid discharge opening, for example, 66B, issupplied with the total flow from two segments 20B and 20C of the thirdflow restricting passage 20; by one-half the flow from each of foursegments 19A, 19B, 19C, 19D of the second flow restricting passage 19and by one-third of the flows from each of six segments 18A, 18B, 18C,18D, 18E, 18F of the first flow restricting passage 18. Thus, it can beseen that if, for example, segments 18C, 19B, and 20B should becomeclogged due to a very poor water quality, the remaining segments wouldstill supply the discharge fluid passing opening 66B, so that a flowwould be maintained to the plants even though the flow would be lessthan the adjoining outlets.

Thus, it can be seen that the total accumulated length of segments 18C,19C, and 20C of the flow restricting passages should be of substantiallygreater length than the distance between two adjacent discharge fluidpassing openings 66 and, at the same time, the flow restricting channelsshould be continuous so that each discharge fluid passing opening issupplied by more than one flow restricting channel segment and more thanone inlet fluid passing opening. By using a long total length offlow-restricting channels, it is possible at the same time to use alarger cross-section in the flow restricting channels and still maintainthe same flow rate. The larger cross sections in the flow restrictingchannels provide a flow path that is less apt to clog from impurities inthe water.

In a similar manner, the flow for each discharge fluid passing opening,for example, 66B, is supplied by 50% of the flow from each of the thirdinlet fluid passages 56A and 56B; by 25% of the flow through each of thesecond inlet fluid passing openings 46A and 46C and 50% of second inletfluid passing opening 46B; and by 25% of the flow through each of fourinlet fluid passing openings 36A, 36B, 36C and 36D (not shown). Again,it can be seen that if, for example, fluid passing openings 36A, 46A or56A should become clogged, the remaining inlet fluid passing openings36B, 36C, 36D, second fluid passing openings 46B, 46C and third fluidpassing opening 56B would supply the discharge fluid passing opening 66.

While an 8 psi inlet water pressure is used to illustrate operation of apreferred embodiment, embodiments incorporating the teachings of thepresent invention will operate at inlet water pressures ranging fromabout 2 psi to 50 or more psi, depending on the strength of wall 22,fluid-passing opening sizes, ratios, etc.

With reference to FIGS. 18 through 24, a method and apparatus formanufacturing a hose embodying the teachings of the subject inventionare disclosed.

Basically, the method and apparatus contemplate the disposition of aplurality of thermoplastic hot melt beads in a parallel relationshipextending longitudinally along the exterior surface of one of themargins of an elongated film. The film is continually advanced andpasses through a molding or forming station where each of the beads isdeformed according to a predetermined pattern to create the variousinlet and outlet stations found in the final hose. The film continues toadvance and eventually passes through a guide which causes the interiorsurface along the other margin to be disposed about the beads. The filmthen advances through the nip of a pair of forming wheels and emerges asthe finally assembled hose.

With continued reference to FIGS. 18 through 24, the details of themethod and apparatus will now be described.

Initially, the impervious film is produced in a flat state. The film isintroduced into the machine by placing it in its flat state under thenozzle 112 of a conventional extrusion nozzle where hot melt beads 113are being extruded, and, at the same time, between the nip of theopposed rolls 122 and 124, which constitute the molding station 114. Thefilm is also folded back upon itself and passed through a stationaryguide member 126 located downstream of the molding station. The film,after passing through the guide station, is received within the nip of apair of forming wheels 115 and 116, which constitute the forming station131. The film emerges from the forming station as the complete hose.During production, the hose is continually advanced by the rotation ofthe forming wheels.

FIGS. 18 through 21 illustrate the details of the molding station 114which basically comprises a pair of rotating wheels 122 and 124. Wheel122 constitutes a bottom wheel and is mounted for rotation on an axis141. Wheel 122 contains a flat cylindrical portion 143 bounded on eitherside by a pair of flange portions 145 and 147.

Wheel 124, which constitutes a top or molding wheel, is disposed abovewheel 122 and rotates about an axis 151 which is essentially parallel tothe rotation axis 141 of the bottom wheel. Wheel 124 has disposed aboutits periphery a number of teeth 153 positioned in a predeterminedarrangement in order to produce a desired indentation pattern in thefinished hose.

FIGS. 18 through 20 provide an example of the type of configuration thatwill produce a hose having an inlet and outlet pattern such as thatshown for the hose in FIGS. 1 through 4. For this arrangement, the wheel124 has a 16 inch circumference. Four molding assemblies 161 through164, each of which contains a predetermined arrangement of teeth 153,are disposed about the circumference at 90° intervals. FIG. 19 shows asectional view of the arrangement of teeth for assemblies 161 and 163,whereas FIG. 20 shows such an arrangement for assemblies 162 and 164. Ascan be seen, beads 30 and 50 are indented at the same time. Beads 40 and60 are also indented at the same time. In this way, the desired patternshown in FIG. 4 is produced. Typically, the teeth have a thickness inthe range from about 0.030 inches to about 0.090 inches depending on thedesired space between the strips.

The circumferences of the wheels 122 and 124 are arranged relative toeach other to provide a nip or space therebetween for receiving thethermoplastic film and the plurality of hot melt beads.

The film and beads pass between the nip rolls 122 and 124 which rotateat the same speed that the film and beads are traveling. As a hot meltbead passes under the teeth in the top nip roll 124, each bead is moldedinto separate longitudinal strips. The top nip roll is spaced from thebottom nip roll at a distance so that, when the film and beads passbetween the nip rolls, beads are slightly flattened within the spacebetween the top and bottom nip rolls.

It is understood that while the preferred method is to start with filmand lay hot melt beads on the film after which the beads are molded intostrips, an alternate method and apparatus is to extrude a one piece flatsheet with parallel longitudinal ridges formed along one margin as itleaves the extrusion die. As an equivalent of the film and beads in thepreferred embodiment, the flat strip with longitudinal ridges, whilestill hot, then passes through a station to mold the strips as in thepreferred embodiment.

While the preferred embodiment describes a rotary molding station, thescope of this invention also includes any method and apparatus foradvancing the film and bead and bringing a mold into contact with thehot melt bead and molding longitudinally spaced apart parallel stripswhich are used for the purpose of both sealing the hose, forming fluidrestricting passages, and permitting flow both between the parallelfluid passages and also to the exterior of the hose. One such method andapparatus would be moving the film and bead under a mold, stopping thefilm and bead momentarily while an overhead molding die comes down uponthe beads to create the strips, then raising the mold die and againadvancing the film and beads thereby, by repeated operation, making acontinual row of parallel and longitudinal hot strips which are thenformed into the hose as in the preferred embodiment.

FIG. 10 shows yet another embodiment for a hose embodying the teachingsof the subject invention. In this arrangement, the distances betweenadjacent inlet stations defined in both strips 50 and 60 have beenreduced so that the distance between adjacent inlet stations 56 is fourinches and the distance between adjacent outlet stations 66 is likewisefour inches. The distances between adjacent inlet stations 36 and 46remain unchanged at eight inches.

The flow path of this type of configuration may be explained withreference to FIGS. 10 and 11, where it can be seen that there are twiceas many openings 56 and 66 as there are openings 46 and 36. If we assumethe flow rate for a given hose with outlets spaced 4 inches apart is 0.6gpm per 100 foot length, the theoretical flow through each opening 56and 66 is 0.002 gpm and the flow through each opening 36 and 46 is 0.004gpm. The flow through segment 20A is 0.001 gpm while the flow throughsegments 18A and 19A are 0.002 gpm. The length of segments 20A and 19Aare 2 inches, while the length of segment 18A is 4 inches. If theconfigurations were used as shown in FIG. 6 but with a 4 inch outletspacing, all of segments 18C, 19B and 20A would be 2 inches, with thetotal combined length of the flow passage segments through which thewater has to travel between the inlet openings 36 and the dischargeopenings 66 being 6 inches. However, with the embodiment illustrated inFIGS. 10 and 11, the total length of the flow passage segments 18A, 19Aand 20A through which the water has to travel between the inlet openings36 and the outlet openings 66 is 8 inches. This longer total combinedlength flow passage produces a greater pressure loss due to friction. Inaddition, the flow rates in flow restricting segments 18A and 19A ofFIG. 10 are twice the flow rate that they would have been in theconfiguration shown in FIG. 6. These higher flow rates in flowrestricting segments 18A and 19A of FIG. 10 produce a still greaterpressure loss. This additional pressure loss reduces the flow ratethrough the discharge openings 66 so that it is possible to have closeroutlet spacing, such as 4 inches, without greatly increasing the totalflow rate from the hose.

Another example of reducing flow rate for a given outlet spacing wouldbe using a 24 inch spacing for inlet openings 36 and 46 and a 12 inchspacing for inlet openings 56 and outlet openings 66.

FIG. 12 shows yet another embodiment where like reference numeralsdenote like elements, and only the differences will be described. Thearrangement of FIG. 12 is similar to that of the first preferredembodiment with the exception that the strip 60 is arranged to include aplurality of closely spaced outlet stations 66' such as 1/4 inch to 1inch apart. This type of arrangement can be advantageously used toirrigate plants growing in a media of extremely porous nature.

As can be appreciated from the foregoing discussion, there are anynumber of arrangements of inlet and outlet station patterns as well asdimensional arrangements for flow-restricting passages, according to therequirements for the area to be irrigated. For example, FIG. 13 shows anarrangement where the inlet stations are each defined by three closelyspaced openings 36A and each outlet station is defined by numerousclosely spaced openings 66A. Further, each of the outlet stations isspaced apart at predetermined distances.

It is often desirable to irrigate flower pots at several intervalsacross the top of the pot so that the entire root area is watereduniformly. The embodiment of FIG. 13 provides an ideal way to irrigate arow of 6 inch flower pots spaced on 12 inch centers. The hose isstretched lengthwise over the top of pots so that there are severaloutlets to drip on each pot. A hose for such an application has inletstations 36A, 46A, and 56A spaced at 12 inch intervals and outletstations 66 spaced at 12 inch centers each consisting of 10 or 12 outletopenings spaced about 1/4 inch apart. This provides a row of drops about21/2 to 3 inches in length in the center of each pot.

A similar application for this embodiment is a row of trees spaced 20feet apart. A hose is run lengthwise of the row and next to the treesand centered on each tree are 12 outlet openings 66 spaced 12 inchesapart with no openings between so that the irrigation is concentratedonly on the area of the tree roots.

Of course, it is to be understood that the various inlet and outletstation configurations may be produced by the method describedhereinbefore by simply arranging the appropriate arrangement of teeth.Thus, it can be seen that, by simply changing the molding wheel, a newpattern may be introduced into the hose without any further change ofthe production equipment.

FIGS. 14 and 15 show yet another embodiment for a hose producedaccording to the teachings of the subject invention. This embodimentcombines the hydraulic principle of pressure loss due to water flowingthrough an orifice and pressure loss due to water flowing through a flowrestricting channel, wherein the flow rate through the orifice changesat approximately a ratio of the square root of the change in pressurewhile the flow rate through the flow restricting channel changesapproximately linearly with the pressure change. This combination givesa flow rate from the outlets 66 that changes in response to pressurechange at a rate somewhere between linear and the square root ofpressure change depending on the structural dimensions of the inletopenings and the length and cross-sectional area of the flow restrictingchannels. This embodiment is similar to that shown in FIG. 4 with theexception that bead 30 is of unitary construction with no indentationsbeing provided. Instead, inlet orifices 36A are provided within the filmto create the fluid communication path between the main supply channel12 and the flow distributing channel 18'. In addition, the flowdistributing channel 18' has a cross-sectional area which is largeenough to allow the flow from each inlet orifice 36A to move through theflow distributing channel 18' to the fluid passing orifices 46 in theimmediate vicinity without substantial pressure loss. At the same time,the flow distributing channel 18' has a cross-sectional area smallenough so that a major portion of the flow from each inlet orifice 36Awill tend to flow out of the fluid passing openings 46 in the immediatevicinity of the inlet orifice 36A. This vicinity will normally consistof a length half way to adjacent inlet orifices 36A. In a typicalembodiment, the inlet openings 36A are approximately 0.024 inches indiameter and spaced about 48 inches apart. The two flow restrictingpassages 19' and 20' are approximately 0.014 inches high and 0.070inches wide and the first, second and third fluid passing openings 46,56 and 66 are on 8 inch centers. With an 8 psi pressure in the mainsupply channel 12, a typical pressure loss across the inlet openingswould be approximately 3 psi and a pressure loss within the first flowrestricting passage 19' would be approximately 3.5 psi withapproximately a 1.5 psi pressure loss within the flow restrictingpassage 20'.

Since the flow rate from the outlets change substantially less than thepressure changes within the main supply channel, it is possible to uselonger rows with the same uniformity than would be possible to use ahose where the outlet flow was linear with pressure.

The hydraulic flow characteristic for the embodiment of FIGS. 14 and 15could be described as a hose with 8 psi in the main supply channel withinlet orifices 36A spaced 48 inches apart and of such a size that eachwill pass 0.02 gpm at a pressure loss of 3 psi, whereupon this 0.02 gpmflow is divided for passage through 6 first fluid passing openings 46,spaced on 8 inch centers, and then is further divided for passage into12 flow restricting passage segments 19A, each approximately 4 inches inlength and of a cross-sectional size so that each segment will carry0.0016666 gpm at a pressure loss of 1.5 psi.

Whereupon there is approximately 0.5 psi pressure loss as the flowpasses through the fluid passing openings 56 into 12 second fluidrestricting passage segments 20A each approximately 4 inches in lengthand of a cross-sectional size so that each segment will carry 0.001666gpm at a pressure loss of approximately 2.9 psi so that the pressurewithin the flow restricting passages 20 adjacent to the outlet openings66 is approximately 0.1 psi whereupon the flow passes through eachspaced outlet openings 66 in the form of a slow drip. The total flowfrom the 150 outlets (or 100 feet of hose) would be 0.5 gpm with a totalpressure reduction of 7.9 psi between main supply channel 12 and a pointwhich is adjacent to the outlet openings and in the flow restrictingpassage 20.

This embodiment is configured so the flow rate out of the outletopenings 66 can be designed to suit the crop by changing the spacing anddiameter of the inlet orifices 36A and/or the cross-sectional dimensionsand length of the flow restricting passages 19' and 20'. Also, the hosecan be made to function so that a major percent of the pressure droptakes place either across the inlet orifice or within the flowrestricting passages.

FIGS. 16 and 17 illustrate yet another embodiment of the hose 10. Asshown in FIGS. 16 and 17, the flow restricting channels 18, 19 and 20are defined in part by an elongated flat film 161 which is of reducedthickness. This film replaces the margin area 24 in the embodiment ofFIG. 4. For this reason, the edge 32 of sheet 22 is secured to themargin 165 of the sheet 161 by a conventional hot melt bead 163. Thereduced thickness of the common wall 161 allows each of the flowrestricting passageways 18, 19 and 20 to be reduced in size and therebycreate a greater friction when the main channel 12 experiences anincrease in water pressure. The reduction in cross-sectional area underthe increase in water pressure is illustrated in FIG. 17.

This embodiment gives a uniform flow from a longer length of row. At theinlet end of the hose, the higher pressure (12 psi, for example) withinthe main channel 12 causes the thinner portion of common wall 161 tostretch and deflect outwardly as in FIG. 17 and into the flowrestricting passages 18, 19 and 20, while at the same time the exteriorcommon wall 26 portion of the flow restricting passages holds its normaldimensions because it is a heavier wall that does not stretchsubstantially. An alternative to using a thinner wall for the sheet 161is to use a material of the same thickness but with a greater ability tostretch under pressure than the material used for common exterior wall26.

This reduces the size of the flow restricting passageways andconsequently reduces the flow through said passageways. As the flowtravels through the main channel 12 in very long lengths of hose, thepressure within is gradually reduced due to friction so that the closedoff end of the main channel 12 has substantially less pressure (6 psi,for example) than the inlet end. The thin common wall 161 at the closedoff end of the hose has less pressure against it and maintains itsnormal circular configuration (FIG. 16) allowing the flow restrictingpassageways to hold their normal cross-sectional area and flow.Therefore, the flow at the inlet end and the closed off end can besubstantially the same even though there is about a 50% loss in pressuredue to friction within the main channel 12. It is understood that thethin section 161 may be a thinner portion of sheet 22 rather than aseparate sheet. The net effect is that the size of the flow restrictingpassages are pressure compensating to give a relatively uniform flowthroughout the length of the hose. Hoses which have thepressure-compensating, flow-restricting passages are suited to fields inwhich the rows run up or downhill, since the flows from the outletsremain relatively even though the pressures within the main flow channelalter with changes in elevation.

While descriptions herein have generally referred to water and fluidpassages, it is understood the same hose can be used for chemicalsolutions such as insecticides, fungicides, fertilizers and alsocompressed air for soil aeration.

Since there is a wide variety of conditions encountered in the field, itis understood that the preferred embodiments are just a few of the manycombinations of ratios and sizes of first fluid-passing openings,spacing of second fluid-passing openings, spacing of dischargefluid-passing openings, cross section of the fourth fluid passages, andpressures introduced into the main supply channel, which fall within thescope and function of this invention.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed is:
 1. For use in a fluid-distributing system for plantsand the like, an elongated fluid-distributing hose having a longitudinalaxis, said hose comprising:an elongated, water-impervious planarmaterial having longitudinally extending margins, said material foldedupon itself to overlap said margins thus defining inner and outermargins, said outer margin defining a first exterior wall and said innermargin defining a second interior wall; a discrete main supply channelbeing adapted for communication with a source of pressurized fluid;first, second and third discrete elongated flow-restricting passagesaligned one next to the other in a common plane and disposed about theexterior of the main supply channel between said interior end exteriorwalls, each passage being essentially parallel to and substantiallyequidistant from the longitudinal axis of said hose, each passage beingcontinuous and uninterrupted throughout the full longitudinal length ofsaid hose; a first wall member secured to said interior and exteriorwalls separating said main supply channel and said first passage; asecond wall member secured to said interior and exterior wallsseparating said first and second passages; a third wall member securedto said interior and exterior walls separating said second and thirdpassages; first fluid-passing stations in said first wall member forpassing fluid directly from said discrete main supply channel passage tosaid first discrete passage; second fluid-passing stations in saidsecond wall member for passing fluid directly from said first discretepassage to said second discrete passage; third fluid-passing stations insaid third wall for passing fluid directly from said second discretepassage to said third discrete passage; and discharge fluid-passingstations from said third passages to the exterior of the hose forpassing fluid directly from said third passage to the exterior of thehose.
 2. The hose of claim 1, wherein the flow length between one ofsaid first inlet stations and one of said outlet stations is at least10% greater than the distance between adjacent outlet stations in saidthird passage.
 3. The hose of claim 1, wherein at least three adjacentlyarranged first inlet stations supply fluid to one of said outletstations.
 4. The hose of claim 1, wherein each of said first inletstations is in fluid communication with at least three of said outletstations.
 5. The hose of claim 1, wherein at least one of said first,second and third wall members comprise a plurality of longitudinallyextending elongated strips disposed lengthwise end to end, thelongitudinal axis of each strip of said first set being substantiallyparallel to and substantially equidistant from the longitudinal axis ofthe hose, the ends of said strips being spaced from each other to definesaid fluid-passing stations.
 6. The hose of claim 1, further comprisinga fourth wall member separating said third passage from the exterior ofsaid hose, and wherein said discharge outlet stations are defined insaid fourth wall member.
 7. The hose of claim 1, wherein each of saidflow-restricting passages is divided into a plurality of adjacentflow-restricting segments, each of said segments being defined by thelength of said passage between the stations in one of the two wallmembers associated with the passage and the nearest station in the otherof the two wall members.
 8. The hose of claim 7, wherein each twoadjacent segments share a common station for receiving the flow of fluidthrough said two adjacent segments.
 9. The hose of claim 8, wherein saidfluid flowing through said two adjacent segments comprises fluid flowingin opposite directions in said passage.
 10. The hose of claim 9, whereinsaid fluid flowing through said two adjacent segments comprises fluidflowing in opposite directions in said passage which meet opposite atsaid common station and pass through said station at approximately aright angle to the longitudinal axis of said passageway.
 11. The hose ofclaim 1 wherein the first exterior wall and the second interior walldefining the flow-restricting passages have no fluid-passing openings.12. The hose of claim 1 wherein the length of the flow passage througheach fluid passing station in adjacent wall members is substantiallylonger than the mean average between the width and height dimensions ofsaid fluid-passing opening.
 13. The hose of claim 1 wherein each inletand outlet station comprises a plurality of closely spaced inlet andoutlet openings sufficient in number and size so that there is a minimumamount of clogging across the station.
 14. The hose of claim 1 whereinthe water drips out of each discharge fluid-passing station undersubstantially quiescent conditions with almost no pressure drop acrosseach discharge station.
 15. The hose of claim 1 wherein all water flowthrough each fluid-passing station and all water flow through saidflow-restricting passages occurs in a plane substantially equidistantfrom the longitudinal axis of said hose.
 16. The hose of claim 1,further comprising a fourth wall member separating said third passagefrom the exterior of the hose, said fourth wall member defined by aplurality of elongated strips disposed lengthwise end to end throughoutthe length of the hose, the longitudinal axis of each strip of saidplurality being substantially parallel to and substantially equidistantfrom the longitudinal axis of said hose, the ends of said strips beingspaced from each other to define said discharge fluid-passing stations.17. The hose of claim 1, wherein the flow from each dischargefluid-passing station is supplied by a portion of a flow-restrictingpassage segment on either side of said discharge station.
 18. The hoseof claim 1, wherein the length of flow travel from a first fluid-passingstation to its nearest discharge fluid-passing station is twice thedistance between adjacent discharge stations.
 19. The hose of claim 1,wherein the flow rate from each discharge station is regulated by theratio of the number of discharge stations to the number of firstfluid-passing stations along with the cross-sectional area of theflow-restricting passage and the total length of flow travel within saidflow-restricting passages.
 20. The hose of claim 1, wherein there aresix discrete pressure reduction steps taking place within the hosebetween the main supply channel and the exterior of the hose.
 21. Thehose of claim 1, wherein said first and second fluid-passing stationsare arranged to cause fluid to pass at a substantially uniform rate fromsaid discharge fluid-passing stations, said discharge stations beingclosely spaced in the range from 0.25 inch to 1.00 inch apart.
 22. Thehose of claim 1, wherein said first and second fluid-passing stationsare arranged to cause fluid to pass at a substantially uniform rate fromsaid discharge fluid-passing stations, said discharge stations spaced atpredetermined distances from each other, certain of said dischargestations defining groups of closely spaced discharge stations, saidgroups being spaced from each other over a predetermined longitudinaldistance of said hose, the portion of said hose within saidpredetermined longitudinal distance having no discharge stations.
 23. Anelongated fluid distributing hose for use in a fluid-distributingsystem, said hose comprising:an elongated, water-impervious planarmaterial having longitudinally extending margins, said material foldedupon itself to overlap said margins thus defining inner and outermargins; a first set of longitudinally extending elongated stripsdisposed end to end between and secured to said overlapping margins, thelongitudinal axis of each strip of said first set being substantiallyparallel to and substantially equidistant from the longitudinal axis ofsaid hose, the ends of said strips of said first set being spaced fromeach other to define outlet stations; a second set of longitudinallyextending elongated strips disposed end to end between secured to saidoverlapping margins, the longitudinal axis of each strip of said secondset being substantially parallel to and substantially equidistant fromthe longitudinal axis of said hose, the ends of said strips of saidsecond set being spaced from each other to define fluid-passingstations; a unitary strip extending longitudinally throughout the fulllongitudinal length of said hose, said unitary strip being disposedbetween and secured to said overlapping margins, the longitudinal axisof said unitary strip being substantially parallel to said axis of saidhose; said first set of strips, said second set of strips, and saidunitary strip being substantially equidistant from the longitudinal axisof said hose; a discrete main supply channel adapted for fluidcommunication with a source of fluid under pressure, said unitary stripand said material defining said discrete main supply channel; at leasttwo discrete elongated flow passages at least one of which is aflow-restricting passage, said at least two passages being defined inpart by said first set of strips, said second set of strips and saidunitary strip, said at least two passages being aligned in a commonplane and disposed about the exterior of said main supply channel, eachpassage being continuous and uninterrupted throughout the fulllongitudinal length of said hose, each passage being essentiallyparallel to and substantially equidistant from the longitudinal axis ofsaid hose; a common wall made of said planar material, said wallsimultaneously defining a portion of said main supply channel and aportion of each of said flow passages; a series of spaced inlet orificesdefined in said common wall for providing fluid communication betweensaid discrete main supply channel and the one of said at least twodiscrete passages formed in part by said second set of strips and saidunitary strip; and said outlet stations are for passing fluid directlyfrom another of said at least two passages to the exterior of said hose.24. The hose of claim 23, wherein each of said outlet stations receivesfluid from two opposite directions within said another passage.
 25. Thehose of claim 23, wherein said another flow-restricting passage includesmeans for altering the cross section in said another passage in responseto a pressure differential between said main supply channel and saidanother passage.
 26. The hose of claim 23 wherein the ratio of thenumber of outlet stations to the number of inlet orifices is greaterthan 2-to-1.
 27. The hose of claim 26 wherein said ratio is 6-to-1. 28.The hose of claim 23, wherein there is a pressure loss across the inletorifices and a further pressure loss within said at least oneflow-restricting passage.
 29. The hose of claim 28 wherein a majorportion of the pressure drop between said main supply channel and saidoutlet stations takes place within said at least one flow-restrictingpassage.
 30. The hose of claim 28 wherein a major portion of thepressure drop between said main supply channel and said outlet stationstakes place across said inlet orifices.
 31. The hose of claim 23,wherein the cross-sectional area of each of the at least two flowpassages and the spacing of said flow stations between each of said atleast two flow passages are configured to provide a uniform flow fromeach of said outlet stations.
 32. The hose of claim 23 wherein eachinlet and outlet station comprises a plurality of closely spaced inletor outlet openings sufficient in number and size so that there is aminimum amount of clogging across the station.
 33. The hose of claim 23wherein the water drips out of each discharge fluid-passing stationunder substantially quiescent conditions with almost no pressure dropacross each discharge station.
 34. The hose of claim 23, wherein theflow rate of each discharge station is regulated (1) by the ratio of thenumber of said inlet orifices to the number of said discharge stations,(2) the area of said inlet orifices, (3) the cross-sectional area ofsaid at least one flow-restricting passage, and (4) the total length offlow travel within said at least one flow-restricting passage.
 35. Thehose of claim 23, wherein said inlet orifices are of predetermined areaand spacing to cause, as flow passes through said orifices, a portion ofthe total pressure drop that occurs within said hose between said mainsupply channel and said outlet stations.
 36. For use in afluid-distributing system for plants and the like, an elongatedfluid-distributing hose, said hose comprising:an elongated,water-impervious planar material having longitudinally extendingmargins, said material folded upon itself to overlap said margins thusdefining inner and outer margins; an elongated, flat sheet having firstand second planar surfaces, a portion of said sheet being disposedbetween said margins; a first set of longitudinally extending elongatedstrips disposed end to end between and secured to said outer margin andthe second planar surface of said flat sheet, the longitudinal axis ofeach strip of said first set being substantially parallel to andsubstantially equidistant from the axis of said hose, the ends of saidstrips of said first set being spaced from each other to definedischarge outlet stations; means longitudinally disposed along thelength of said hose for securing the longitudinal edge of said firstplanar surface to said inner margin; a second set of longitudinallyextending elongated strips disposed end to end between and secured tosaid outer margin and the second planar surface of said flat sheet, thelongitudinal axis of each strip of said second set being substantiallyparallel to and substantially equidistant from the axis of said hose,the ends of said strips of said second set being spaced from each otherto define fluid-passing inlet stations; said first and second sets ofstrips being substantially equidistant from the longitudinal axis ofsaid hose; said second set of strips, said flat sheet, and said materialdefining a main discrete supply channel being adapted for communicationwith a source of pressurized fluid; said first and second sets ofstrips, said outer margin and said flat sheet defining at least onediscrete flow-restricting passage disposed about the exterior of themain supply channel; said second set of strips defining a first wallmember separating said main supply channel and said passage; saidfluid-passing inlet stations in said first wall member for fluidcommunication between said main supply channel and said passage; saiddischarge fluid-passing outlet stations for passing fluid directly fromsaid passage to the exterior of the hose; and said flat sheet being ofgreater deflectability than said outer margin for causing said flatsheet to move to change the cross-sectional size of said at least oneflow-restricting passage in response to pressure changes in the mainsupply channel thereby compensating for the pressure changes so that theflow from the outlet stations tends to remain uniform.
 37. The hose ofclaim 36, wherein each of said at least one flow-restricting passage iscontinuous and uninterrupted throughout the full longitudinal length ofsaid hose.
 38. The hose of claim 36, wherein the water drips out of eachdischarge fluid-passing station under substantially quiescent conditionswith almost no pressure drop across each discharge station.
 39. For usein a fluid-distributing system for plants and the like, an elongatedfluid-distributing hose having a longitudinal axis, said hosecomprising:an elongated, water-impervious planar material havinglongitudinally extending margins, said material folded upon itself tooverlap said margins thus defining inner and outer margins; a first setof longitudinally extending elongated strips disposed end to end betweenand secured to said overlapping margins, the longitudinal axis of eachstrip of said first set being substantially parallel to andsubstantially equidistant from the longitudinal axis of said hose, theends of said strips of said first set being spaced from each other todefine first fluid-passing inlet stations; a second set oflongitudinally extending elongated strips disposed end to end betweenand secured to said overlapping margins, the longitudinal axis of eachstrip of said second set being substantially parallel to andsubstantially equidistant from the longitudinal axis of said hose, theends of said strips of said second set being spaced from each other todefine second fluid-passing inlet stations; a third set oflongitudinally extending elongated strips disposed end to end betweenand secured to said overlapping margins, the longitudinal axis of eachstrip of said third set being substantially parallel to andsubstantially equidistant from the longitudinal axis of said hose, theends of said strips of said third set being spaced from each other todefine fluid-passing outlet stations; said first, second and third setsof strips being substantially equidistant from said longitudinal axis ofsaid hose; said material defining a discrete main supply channel beingadapted for communication with a source of pressurized fluid; said firstand second sets of strips and said inner and outer overlapping marginsdefining a first discrete, elongated flow-restricting passage disposedabout the exterior of the main supply channel, said passage beingessentially parallel to the longitudinal axis of said discrete mainsupply channel, said passage being continuous and uninterruptedthroughout the full longitudinal length of said hose; said second andthird sets of strips and said inner and outer overlapping marginsdefining a second discrete, elongated flow-restricting passage disposedabout the exterior of the main supply channel, said passage beingessentially parallel to the longitudinal axis of said discrete mainsupply channel, said passage being continuous and uninterruptedthroughout the full longitudinal length of said hose; said inner marginsimultaneously defining a portion of each of said flow-restrictingpassages and said main supply channel; said second set of stripsdefining a wall member between said first and second flow-restrictingpassages; and said second fluid-passing inlet stations in said firstwall member providing fluid communication between said first passage andsaid second passage.
 40. For use in a fluid-distributing system forplants and the like, an elongated fluid-distributing hose having alongitudinal axis, said hose comprising:an elongated, water-imperviousplanar material having longitudinally extending margins, said materialfolded upon itself to overlap said margins thus defining inner and outermargins, said outer margin defining a first exterior wall and said innermargin defining a second interior wall; a discrete main supply channelbeing adapted for communication with a source of pressurized fluid;first, second and third discrete elongated flow passages aligned onenext to the other in a common plane and disposed about the exterior ofthe main supply channel between said interior and exterior walls, eachpassage being essentially parallel to and substantially equidistant fromthe longitudinal axis of said hose, each passage being continuous anduninterrupted throughout the full longitudinal length of said hose; afirst wall member secured to said interior and exterior walls separatingsaid main supply channel and said first passage; a second wall membersecured to said interior and exterior walls separating said first andsecond passages; a third wall member secured to said interior andexterior walls separating said second and third passages, at least saidsecond and third passages being flow-restricting passages; first fluidpassing stations in said first wall member for passing fluid directlyfrom said discrete main supply channel passage to said first discretepassage; second fluid-passing stations in said second wall member forpassing fluid directly from said first discrete passage to said seconddiscrete passage; third fluid-passing stations in said third wall forpassing fluid directly from said second discrete passage to said thirddiscrete passage; and discharge fluid-passing stations from said thirdpassage to the exterior of the hose for passing fluid directly from saidthird passage to the exterior of the hose.
 41. For use in afluid-distributing system for plants and the like, an elongatedfluid-distributing hose having a longitudinal axis, said hosecomprising:an elongated, water-impervious planar material havinglongitudinally extending margins, said material folded upon itself tooverlap said margins thus defining inner and outer margins, said outermargin defining a first exterior wall and said inner margin defining asecond interior wall; a discrete main supply channel being adapted forcommunication with a source of pressurized fluid; first, second andthird discrete elongated flow passages aligned one next to the other ina common plane and disposed about the exterior of the main supplychannel between said interior and exterior walls, each passage beingessentially parallel to and substantially equidistant from thelongitudinal axis of said hose, each passage being continuous anduninterrupted throughout the full longitudinal length of said hose; afirst wall member separating said main supply channel and said firstpassages; a second wall member separating said first and secondpassages, said second wall member being defined by a first set oflongitudinally extending elongated strips disposed end to end betweenand secured to said overlapping margins, the longitudinal axis of eachstrip of said first set being substantially parallel to andsubstantially equidistant from the longitudinal axis of said hose, theends of said strips of said first set being spaced from each other todefine first fluid-passing stations; a third wall member separating saidsecond and third passages, said third wall member being defined by asecond set of longitudinally extending elongated strips disposed end toend between and secured to said overlapping margins, the longitudinalaxis of each strip of said second set being substantially parallel toand substantially equidistant from the longitudinal axis of said hose,the ends of said strips of said second set being spaced from each otherto define second fluid-passing stations; means at longitudinally spacedintervals for passing fluid from said main supply channel to said firstdiscrete passage, each of said fluid passing means comprising a singleopening or a series of closely spaced openings; said first fluid-passingstations in said second wall member for passing fluid directly from saidfirst discrete passage to said second discrete passage; said secondfluid-passing stations in said third wall for passing fluid directlyfrom said second discrete passage to said third discrete passage; anddischarge fluid-passing stations from said third passage to the exteriorof the hose for passing fluid directly from said third passage to theexterior of the hose.
 42. The hose of claim 41, wherein said first wallmember comprises a unitary strip extending longitudinally throughout thefull longitudinal length of said hose, said unitary strip being disposedbetween and secured to said overlapping margins, the longitudinal axisof said unitary strip being substantially parallel to said axis of saidhose.
 43. The hose of claim 41 wherein there is a pressure loss acrossmeans for passing fluid from said main supply channel to said firstdiscrete passage and a further pressure loss within at least one of saidfirst, second, and third discrete elongated flow passages.
 44. The hoseof claim 43 wherein a major portion of the pressure drop between saidmain supply channel and said outlet stations takes place within at leastone of said first, second, and third discrete elongated flow passages.45. The hose of claim 43 wherein a major portion of the pressure dropbetween said main supply channel and said outlet stations takes placewithin said means for passing fluid from said main supply channel tosaid first discrete passage.